The NFL is conducting an “ongoing and comprehensive” investigation into the allegations that PEYTON MANNING used illegal human growth hormone while recovering from neck surgery back in 2011.

The initial report came out last month, and claimed that Peyton’s wife Ashley received deliveries of HGH from an Indianapolis anti-aging clinic under her name, supposedly in an effort to keep Peyton from being connected to it.

The tip reportedly came from a former pharmacy intern named Charles Sly. But he already recanted the story.

Several weeks ago, Manning denied everything . . . quote, “The allegation that I would do something like that is complete garbage and is totally made up. It never happened. Never. I really can’t believe somebody would put something like this on the air. Whoever said this is making stuff up.”

The NFL didn’t put a timetable on the investigation, but did note that it will not be completed before next week’s Super Bowl.